Author Topic: UNI-T UT61E Multimeter teardown photos.  (Read 534356 times)

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Offline Salas

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #475 on: December 11, 2012, 07:25:10 pm »
87V still 10mA, 17B still 9.98mA, 61E improved to 9.989mA. All in series closing circuit. Burden change helps 61E by 0.039mA even at 20V and 2K source resistance (PSU and 2K dummy in series).
 

Offline alexig

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #476 on: January 02, 2013, 11:30:35 am »
Just received this multimeter and found something strange with it.

If I switch to the mA scale with no leads in and press the peak button, it gives me a reading of 0.21 for the Pmax and -0.25 for Pmin (both values start rising after a second or two). Same thing happens in the uA range, I get 1.8uA Pmax and -3.4uA Pmin.

If I measure the current going through a 10K resistor using a 3V battery, my Pmax rises to 0.46 to 0.53mA and Pmin as -0.012mA. Now if I leave it in peak mode, plug and unplug the load the readings go up again, Pmax goes up slightly but Pmin goes up to -0.43mA.

When measuring peak voltage of a 3V battery, Pmax slowly starts increasing and goes 30-60mV above the live reading, Pmin looks to be ok. When you disconnect and reconnect the battery Pmax reads 3.35V and Pmin reads -0.1V.

In mA mode, when I press peak and then it says CAL the number 0.834V shows up before going to -28V and then the real Pmax reading - sounds like the calibration is wrong, should it be 0V and then jump to -28V?

When the leads are out the mV selection seems to jump around quite a lot, when turned on it rises to 70mV and drops to -30mV and starts slowly increasing to -27mV, none of my other meters do this. If you pick it up and move it around or move your hands around it, it jumps all over the place and can sometimes go to overload.

Does this happen to anyone else?
« Last Edit: January 02, 2013, 11:36:09 am by alexig »
 

Offline dr_p

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #477 on: January 02, 2013, 02:05:24 pm »
Plug in leads and short them, see the 0.000mA or 0.000V and be happy. You don't use it without the leads attached.

3V(sure?) on 10K(sure?) is 0.3mA. Add not perfect contact resistance and/or component tolerances and you're reading of 0.46mA...0.53mA is fine. Peak min is minus something(close to 0) because you started peak mode before connecting the resistor. What do you expect?

The single "wrong" thing is the "CAL" event, but that stinks too - the meter shows Volts readings, and you want to measure mA. Judging from your other problems, are you sure you know how to use the meter? Like plug the leads in the correct sockets?

 

Offline alexig

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #478 on: January 02, 2013, 02:54:56 pm »
Yes when the leads are shorted it does read 0mA or 0V, it's I thought the Pmax/Pmin would work differently. Pmin I'm not too worried about but Pmax is odd to me.

I can confirm the battery voltage is 2.966V and 10K resistor reads 9.849K. The odd thing is that when I have the live reading it's 0.295mA which is all good but then I press peak, it says CAL and then Pmax goes to 0.4mA and then to 0.5mA,

Maybe I'm missing something about the physics of electronics but shouldn't the current constantly stay very close to 0.295mA and not fluctuate if I'm touching anything in the circuit? I would have expected Pmax to be a few mV higher than the live reading.
 

Offline dr_p

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #479 on: January 02, 2013, 04:37:39 pm »
The manual - pg.12 and pg.39:   "CAL" means the meter enters self-calibrating mode and should be allowed to finish (e.g. don't press any key)

You did read the manual, right? :)
 

Offline alexig

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #480 on: January 03, 2013, 09:22:09 am »
Yep I have been reading the manual, when I press peak I don't press any other key until it's finished the CAL and only press peak again when the result looks similar to the live reading (after 6 seconds). When I short the leads in the current mA mode and press peak, it gives 0.2mA as Pmax. If I do the same in the Amp mode, it gives 0.3Amps.
 

Offline T4P

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #481 on: January 04, 2013, 06:10:10 am »
Jeez. Always read the manual next time or else  :-BROKE
 

Online Monkeh

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #482 on: January 14, 2013, 08:02:27 pm »
So, further to my fuse upgrade, I'm likely to be placing a Farnell order sometime soon, and was thinking of whacking a couple of these in: http://uk.farnell.com/bourns/2095-80-blf/gas-discharge-tube-2p-800v-20/dp/2118242

Comments, alternative suggestions? (note any MOV capable of handling those discharge levels by itself is not going to physically fit).

UT61E haters need not apply.
 

Offline T4P

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #483 on: January 15, 2013, 06:37:09 am »
Yes, that was my gripe. I couldn't find a MOV easily with decent specs and certainly i don't have a MOV "recommended" rating list for DMMs
Looks like i'm getting GDTs instead  :)
I had been considering ERZV10D112 MOVs at first but then i realized 10mm discs are pretty small ... i nearly thought 10mm was huge
 

Offline Rick Law

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #484 on: January 31, 2013, 02:59:50 am »
Ah ha Mr. iloveelectronics,

I saw on your signature lines about having some UT61E to sell at your eBay store99centHobbies.com, and rather than dealing with an unknown ebay seller, I decided to get it from you.

Having deciding to purchase, a brain-freeze moment hits...  I click the tab back to ebay and click purchase there!

Well, anyhow, I hope to receive the UT61E soon.  So, stop blogging, and get to work!  (just kidding)

Rick Law
-----------------------------------



Someone find 61E about less $60 with shipping  HK or SG post? China air mail can not taking out multimeter almoust 1.5 mounth.(((

I live in Hong Kong and can get hold of the UT 61E rather easily at a cost of around $40 including shipping from China to me. Depending on where you are, I should be able to ship one out through HK post (which is quite reliable and relatively quick comparing to China post), within your budget. I'm happy to help but obviously trust will be an issue as we are strangers to each other and merely fellow forum members. If you do want me to help let me know.
 

Offline iloveelectronics

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #485 on: January 31, 2013, 03:17:24 am »
Ah ha Mr. iloveelectronics,

I saw on your signature lines about having some UT61E to sell at your eBay store99centHobbies.com, and rather than dealing with an unknown ebay seller, I decided to get it from you.

Having deciding to purchase, a brain-freeze moment hits...  I click the tab back to ebay and click purchase there!

Well, anyhow, I hope to receive the UT61E soon.  So, stop blogging, and get to work!  (just kidding)

Rick Law
-----------------------------------

Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky
My email address: franky @ 99centHobbies . com
My eBay store: http://stores.ebay.com/99centhobbies
 

Offline Rick Law

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #486 on: January 31, 2013, 03:38:58 am »
Found this nifty gadget,

http://www.voltagestandard.com/DMMCheck.html

for those who wants to caliibarate thier DMM,though not necessary for Ut61E cuz already very tuned,but because pots are their it is possible


Mr. Dimitrioptimus,

Thank you for pointing this out!  For those of us wondering if the DMM is still (or ever) accurate, this really helps.  I just ordered the UT61E.  I suppose I wont need it for a few months yet.  But 12 months mark looks like the right time to adjust for the shifts.
 

Offline Rick Law

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #487 on: January 31, 2013, 04:21:19 am »
To clean the terminals with cotton bar with detergent, as dirt or moisture in the terminals can affect readings
Not exactly english but they tried their best to translate, i've seen worst manuals from some "top" companies on their low-end products which are clearly some rebadged stuff (Or re-fried sick if you prefer)
Interpreted as : Clean the terminals with a cotton bar with some detergent periodically as dirt or moisture buildup can affect readings ... though i don't agree with the detergent part.

I would guess "cotton bar" is "cotton swabs" or more commonly call "Q-tips" in the USA.  I am not sure they use "detergent" to mean "cleaning agent" or really the soap-based detergent we use for dishes.  But soap based detergent is certainly a possibility.

I have actually cleaned the inside of a smart phone using dish-detergent after I dropped it in sea-water while at the beach.  I rinsed it in clean (tap) water immediately after I picked it up from the 1-2 foot deep sea-water.  It was dripping sea water as I walked back to the hotel.  I packed it wet after a good tap-water rinse at the hotel's "foot rinse" (they don't want sand in the hotel).  I kept it wet until I got home the next day.  At home, I can clean it properly.  After disassembling the phone exposing the motherboard (and daughter board which the radio is on) I washed everything with tap water and detergent again.  I then rinsed it in alcohol, dried it by my air-conditioning vent (till I think it is visibly dried plus another day and half).  Reassembled them and go.  The smart phone (Treo 650) is still in use.  I just love that darn phone and don't want to switch.

I also detergent washed some PC components.  My home server (an IBM eServer from eBay) had a fan board that failed (with much gook and gunk almost like black-jelly on it that I don't even want to touch).  I washed the board in dish-detergent (water rinse then alcohol rinsed/wiped).  I did that a few months ago and brought that fan board back to life.  The darn thing is still working with the board driving the fans properly.

So, may be they do mean regular washing detergent - perhaps not enough to be dripping but just enough to moisten the tip of the cotton swab.  Perhaps then a round of water-moisten swabbing to take out the detergent, then final a swabbing with alcohol.  That would be my guess.

If you try that, it would be at your own risk.  I certainly feel comfortable doing that.  My smart phone bath was the first "forced" experiment having dropped it into the sea - I was uncomfortable, but I know that was how a wet camera got fixed, so I just tried.  When I washed my server, I knew what I was doing then and was more confident doing it.  I certainly would be comfortable wiping connection joints, jacks, sockets, etc. with detergent then water then final wipe with alcohol.

Rick Law
 


Offline Teneyes

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #489 on: February 03, 2013, 07:53:07 am »
Thanks Franky ,   
  Received in Canada 11 days after shipping, as expected, 4 days to Vancouver plus another 7 days  to Me.
 I ordered another one today as gift for my older brother, who is using analog Meter :bullshit: 5000ohms/v
This Brother got me started with a Heathkit (EK1)  Christmas gift, when I was 10 years old
Yeah  I'm old now
« Last Edit: February 03, 2013, 07:56:27 am by Teneyes »
IiIiIiIiIi  --  curiosity killed the cat but, satisfaction brought it back
 

Offline Rick Law

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #490 on: February 11, 2013, 05:47:44 pm »
Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky

Forgive me, guys, I have to blow some steam here.  Franky shipped the package same or next day (scanned/acceptance by HK post next day), that was very quick.  (Thanks Franky)

The package got to San Francisco on February 5th. 5am.   I thought, gee, I get mail from San Francisco in a couple of days.  So I have been checking, and checking, and checking, hoping to get to play with it over the weekend...   That was not to be.  I check again this morning, and the package just left San Francisco this morning, February 11th, 0:00am.  5 days and 19 hours it stayed in San Francisco to get on a truck heading East.  I hope it doesn't stop in Ohio or something before it hit the East Coast where I am.  Life is not that long; I want to get my hand on my new toy before I am stone cold and mummified...

Well, perhaps it was US Customs.  Let see if I get a US custom sticker on it (they did that once after they opened the package for inspection and re-close it with a US Customer sticker)...

I must say, most of the stuff I ordered from HK/China got here pretty quick.  About 1 in 10 takes forever.  Geez, I was really hoping to get my hands on it over the weekend of LAST week.

Rick

By-the-way, Franky, "Kung Hai Fat Choi".  In fact, "Kung Hai Fat Choi" to everyone - that is "Happy Chinese New Year" to everyone & best to all of you and your family...  Chinese New Year was yesterday.  The Chinese will be saying "Kung Hai Fat Choi" to everyone for the next week or so.  Franky is probably away gone somewhere to "Fat Choi" right now. 
 

Offline T4P

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #491 on: February 11, 2013, 05:59:25 pm »
Nah, it's still chinese new year ... for china at least it's 10 whole days
 

Offline Eliminateur

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #492 on: February 13, 2013, 06:28:18 pm »
Hmm i have a question/gripe about the UT61e:
one of the first tests i made was AC line voltage, which showed 232V (which is the correct RMS value of line voltage) then i used the peak funciton, hoping to record line variations, to my surprise it showed 328VAC as peak high...
so wwwait, shouldn't peak AC retain RMS value?, not absolute peak?, kind of confusing when used with AC.... would've much preferred the peak RMS value (which is the readout i'm getting normally)
 

Offline Wytnucls

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #493 on: February 13, 2013, 06:39:41 pm »
'Peak Hold' has a fast update rate to capture top and bottom of sine wave. So, the 61E meter behaves quite normally on that setting.
Max/Min selection, with a slower capture speed, would show RMS fluctuations, but the 61E meter doesn't have that feature.
 

Offline Eliminateur

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #494 on: February 13, 2013, 06:43:41 pm »
i see...
it's just a matter of "wording" then, peak is doing literally that when i was expecting a min/max

oh well i can live with that it's not a feature i'm going to using much in AC (i'll use it on DC).

BTW, i there a way to indirectly measure temperature on the UT61E with the adapter connected?, maybe in the mA range and some conversion table?
 

Offline Wytnucls

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #495 on: February 13, 2013, 07:12:42 pm »
I'm not sure which adapter you're talking about.
A thermocouple wil give you a voltage based on absolute temperature. You still need ambient temp measurement at the base for a meaningful temperature indication.
Dave just did a video on the subject. Go look it up.
 

Offline T4P

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #496 on: February 13, 2013, 07:21:15 pm »
so wwwait, shouldn't peak AC retain RMS value?, not absolute peak?, kind of confusing when used with AC.... would've much preferred the peak RMS value (which is the readout i'm getting normally)
PEAK is basically what it is, the peak value of the wave not a min/max kind of thing
 

Offline Rick Law

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #497 on: February 14, 2013, 06:50:39 pm »
Hi Rick,

Your multimeter has been packed and ready to be shipped out today :)

Cheers,
Franky

Thanks Franky -  I got it yesterday, checked it out last night.  Works well!

I knew you shipped very quickly - according to post office tracking they got the package in tracking the next day.  Unusually this package 5 days 19 hour vacation in San Francisco before it headed east.  That was unusual.  No sign of US customs handling it, so I wonder what it did in San Francisco that long.

By the way, thanks to you folks here on this blog (and thanks, Mr. MJ Lorton.  Your YouTube reviews led me to this DMM).  I know exactly what to expect, and I know how this will serve me and where it will fail me so I made my choice with confidence.   Thanks, guys!  You folks have been most informative and the information you shared have been helpful.

So far, my only disappointment is my old USB-RS232 adapter doesn't work.  The UT61E and software are fine since they work with my old PC with a real RS232 port.  Ironically, I get this DMM to track this old PC's power supply which I suspect is failing...  Well, I guess a new USB-RS232 dongle is now on my agenda.

Rick
 

Offline notsob

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Re: UNI-T UT61E Multimeter teardown photos.
« Reply #498 on: February 14, 2013, 08:20:35 pm »
There is a USB adaptor option for the UT61E instead of the supplied RS232 one - ask Franky.
 

Offline Lightages

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